1. Field of the Invention
The embodiments described herein relate generally to a method and systems to facilitate reducing interference between at least two radio frequency (RF) signals and, more particularly, to a method and systems to facilitate reducing interference between Global System for Mobile Communications (GSM) signals and RF signals.
2. Description of the Related Art
At least some RF signals are GSM signals. More specifically, GSM signals are used in some known cellular telephone systems. The GSM standard uses Time Division Multiple Access (TDMA) to allow multiple telephones to communicate simultaneously with a base station. GSM cellular telephones transmit data in bursts at a rate of 217 Hz. As such, an electric field strongly modulated at 217 Hz results from transmissions of the GSM cellular telephones. At least some known GSM devices operate at frequencies ranging between 800 MHz to 1900 MHz, however, the 217 Hz envelope frequency is consistent. Further, the frame structure according to the GSM standard includes eight time slots per frame. Each GSM device in communication with the base station uses only one time slot per frame for communicating with the base station.
At least some RF devices, other than GSM devices, transmit RF signals within the same frequency range as GSM devices. However, RF signals transmitted by other RF devices may have a power level that is less than the power level of the GSM signals such that the GSM signals interfere with the transmission/reception of the other RF signals. As such, when a GSM device and another RF device that transmit within the same or overlapping frequencies are used proximate each other, the GSM signal interferes with the other RF signals by dominating the frequency such that the RF signal is not properly received. More specifically, when an RF transmitter-receiver is positioned at a distance from a GSM transmitter-receiver at which GSM signals overpower other RF signals, the RF transmitter-receiver does not properly receive RF signals other than the GSM signals. Furthermore, even where a GSM signal and another RF signal are not transmitted on overlapping frequencies, harmonics of one of the signals may occupy the same range of RF spectrum as the other signal. Accordingly, a need exists for a system and/or method for allowing GSM devices and other RF devices transmitting within the same or overlapping frequencies, or emitting interfering harmonics, to be used within a close proximity of each other such that interference between GSM signals and other RF signals is reduced.